Alternative transient eddy-current flowmetering methods for liquid metals

Richard Looney; Janis Priede

doi:10.1016/j.flowmeasinst.2018.11.011

Alternative transient eddy-current flowmetering methods for liquid metals

Richard Looney, Janis Priede

Research Centre for Fluid and Complex Systems

Research output: Contribution to journal › Article › peer-review

4 Citations (Scopus)

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Abstract

We present a comprehensive numerical analysis of alternative transient eddy-current flowmetering methods for liquid metals. This type of flowmeter operates by tracking eddy-current markers excited by the magnetic field pulses in the flow of a conducting liquid. Using a simple mathematical model, where the fluid flow is replaced by a translating cylinder, a number possible alternative measurement schemes are considered. The velocity of the medium can be measured by tracking zero crossing points and spatial or temporal extrema of the electromotive force (emf) induced by transient eddy currents in the surrounding space. Zero crossing points and spatial extrema of the emf travel synchronously with the medium whereas temporal extrema experience an initial time delay which depends on the conductivity and velocity of the medium. Performance of transient eddy-current flowmetering depends crucially on the symmetry of system. Eddy current asymmetry of a few per cent makes the detection point drift with a velocity corresponding to a magnetic Reynolds number $Rm\sim 0.1.$ With this level of asymmetry transient eddy-current flowmetering can be reliably applicable only to flows with $Rm\gtrsim 0.1.$ A more accurate symmetry adjustment or calibration of flowmeters may be necessary at lower velocities.

Original language	English
Pages (from-to)	150-157
Number of pages	8
Journal	Flow Measurement and Instrumentation
Volume	65
Early online date	15 Nov 2018
DOIs	https://doi.org/10.1016/j.flowmeasinst.2018.11.011
Publication status	Published - Mar 2019

Bibliographical note

NOTICE: this is the author’s version of a work that was accepted for publication in Flow Measurement and Instrumentation. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Flow Measurement and Instrumentation, 65, (2019)
DOI: 10.1016/j.flowmeasinst.2018.11.011

© 2019, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

Keywords

Electromagnetic flowmeter
Liquid metal
Eddy current

Access to Document

10.1016/j.flowmeasinst.2018.11.011

Post-PrintAccepted author manuscript, 775 KBLicence: CC BY-NC-ND

Cite this

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title = "Alternative transient eddy-current flowmetering methods for liquid metals",

abstract = " We present a comprehensive numerical analysis of alternative transient eddy-current flowmetering methods for liquid metals. This type of flowmeter operates by tracking eddy-current markers excited by the magnetic field pulses in the flow of a conducting liquid. Using a simple mathematical model, where the fluid flow is replaced by a translating cylinder, a number possible alternative measurement schemes are considered. The velocity of the medium can be measured by tracking zero crossing points and spatial or temporal extrema of the electromotive force (emf) induced by transient eddy currents in the surrounding space. Zero crossing points and spatial extrema of the emf travel synchronously with the medium whereas temporal extrema experience an initial time delay which depends on the conductivity and velocity of the medium. Performance of transient eddy-current flowmetering depends crucially on the symmetry of system. Eddy current asymmetry of a few per cent makes the detection point drift with a velocity corresponding to a magnetic Reynolds number $Rm\sim 0.1.$ With this level of asymmetry transient eddy-current flowmetering can be reliably applicable only to flows with $Rm\gtrsim 0.1.$ A more accurate symmetry adjustment or calibration of flowmeters may be necessary at lower velocities. ",

keywords = "Electromagnetic flowmeter, Liquid metal, Eddy current",

author = "Richard Looney and Janis Priede",

note = "NOTICE: this is the author{\textquoteright}s version of a work that was accepted for publication in Flow Measurement and Instrumentation. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Flow Measurement and Instrumentation, 65, (2019) DOI: 10.1016/j.flowmeasinst.2018.11.011 {\textcopyright} 2019, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ ",

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doi = "10.1016/j.flowmeasinst.2018.11.011",

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AU - Looney, Richard

AU - Priede, Janis

N1 - NOTICE: this is the author’s version of a work that was accepted for publication in Flow Measurement and Instrumentation. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Flow Measurement and Instrumentation, 65, (2019) DOI: 10.1016/j.flowmeasinst.2018.11.011 © 2019, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

PY - 2019/3

Y1 - 2019/3

N2 - We present a comprehensive numerical analysis of alternative transient eddy-current flowmetering methods for liquid metals. This type of flowmeter operates by tracking eddy-current markers excited by the magnetic field pulses in the flow of a conducting liquid. Using a simple mathematical model, where the fluid flow is replaced by a translating cylinder, a number possible alternative measurement schemes are considered. The velocity of the medium can be measured by tracking zero crossing points and spatial or temporal extrema of the electromotive force (emf) induced by transient eddy currents in the surrounding space. Zero crossing points and spatial extrema of the emf travel synchronously with the medium whereas temporal extrema experience an initial time delay which depends on the conductivity and velocity of the medium. Performance of transient eddy-current flowmetering depends crucially on the symmetry of system. Eddy current asymmetry of a few per cent makes the detection point drift with a velocity corresponding to a magnetic Reynolds number $Rm\sim 0.1.$ With this level of asymmetry transient eddy-current flowmetering can be reliably applicable only to flows with $Rm\gtrsim 0.1.$ A more accurate symmetry adjustment or calibration of flowmeters may be necessary at lower velocities.

AB - We present a comprehensive numerical analysis of alternative transient eddy-current flowmetering methods for liquid metals. This type of flowmeter operates by tracking eddy-current markers excited by the magnetic field pulses in the flow of a conducting liquid. Using a simple mathematical model, where the fluid flow is replaced by a translating cylinder, a number possible alternative measurement schemes are considered. The velocity of the medium can be measured by tracking zero crossing points and spatial or temporal extrema of the electromotive force (emf) induced by transient eddy currents in the surrounding space. Zero crossing points and spatial extrema of the emf travel synchronously with the medium whereas temporal extrema experience an initial time delay which depends on the conductivity and velocity of the medium. Performance of transient eddy-current flowmetering depends crucially on the symmetry of system. Eddy current asymmetry of a few per cent makes the detection point drift with a velocity corresponding to a magnetic Reynolds number $Rm\sim 0.1.$ With this level of asymmetry transient eddy-current flowmetering can be reliably applicable only to flows with $Rm\gtrsim 0.1.$ A more accurate symmetry adjustment or calibration of flowmeters may be necessary at lower velocities.

KW - Electromagnetic flowmeter

KW - Liquid metal

KW - Eddy current

U2 - 10.1016/j.flowmeasinst.2018.11.011

DO - 10.1016/j.flowmeasinst.2018.11.011

M3 - Article

SN - 0955-5986

VL - 65

SP - 150

EP - 157

JO - Flow Measurement and Instrumentation

JF - Flow Measurement and Instrumentation

ER -

Alternative transient eddy-current flowmetering methods for liquid metals

Abstract

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Keywords

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